I. Field of the Invention
The present invention relates generally to the field of waste water treatment systems. More particularly, the present invention relates to a drip field manifold system which prevents over saturation of a drip field.
II. Description of the Related Art
Drip fields are commonly utilized with waste water treatment systems for the disposal of effluent into the soil. The) are especially useful with land lots having steep grades, rocky terrain, high water tables or soil with low percolation rate capability. Drip fields generally comprise an inlet and an outlet manifold with a plurality of substantially parallel drip lines connected therebetween acting in concert to discharge the effluent from the given waste water treatment system into the soil. Further, the waste water treatment systems are designed with timers to periodically shut off effluent flow to the drip field to prevent over saturation. To assist in preventing over saturation of a portion of the drip field, the drip lines are typically disposed substantially perpendicular to the slope of the grade and along the contour of a portion of the land lot. The manifolds accordingly are disposed substantially parallel to the slope. A drip line often comprises a pressure-induced, water-emitting drip hose having either above or below ground drip emitters. In another configuration, the drip lines are disposed substantially parallel to the slope of the grade with the inlet manifold being at a higher elevation than the discharge manifold.
Unfortunately, either configuration for the drip field arrangement fails to prevent over saturation, which can result in effluent run-off causing waste water contamination of ground water or local lakes and streams. Even though effluent flow from the waste water treatment system to the drip field is periodically terminated, the effluent remaining in the manifolds and the drip lines continues to flow down grade due to gravity and is discharged at the lower most drip line, commonly through the lower most drip emitters, because the individual drip lines are not isolated from one another. Additionally, previously discharged effluent can be siphoned back into the upper most drip lines and thereby redirected to the lower most drip line and discharged, adding to the over saturation problem. Also, the upper most drip lines can act as drains by receiving previously discharged effluent which back flows through the drip emitters and is redirected to the lower most drip line to be discharged, adding to the over saturation problem as well. Much effort has been expended in the waste water treatment industry to eliminate the problem of over saturation of a portion of the drip field, and until now, without success.
In U.S. Pat. No. 5,200,065, I describe a tertiary waste treatment and disposal system having a drip field. The drip field has an upper manifold, a lower manifold and drip lines extending from the upper manifold to the lower manifold. In this configuration, the drip lines are not isolated from one another and the effluent remaining in the manifolds continue to drain through drip emitters of the drip lines even after the flow of effluent from the waste treatment system is discontinued. Since the manifolds run the length of the drip field, a significant amount of effluent is capable of being retained within the manifolds.
U.S. Pat. No. 5,441,631 issued to Stegall, Sr., et al also describes a waste treatment system having a drip field. As shown in FIGS. 1 and 2 thereof, the drip field has a manifold and drip line configuration similar to the one described in U.S. Pat. No. 5,200,065.
Harry, III, describes a sewage effluent disposal system having sparger in holding tank in U.S. Pat. No. 5,597,477. Referring particularly to FIG. 2 thereof, this system also has a drip field, but the drip lines are in a looped arrangement extended between a discharge manifold and a return manifold. Again, the drip lines are not isolated from one another because the manifolds are perpendicular to the drip lines and extend the length of the drip field, enabling the same problems of over saturation because the upper most drip line is operably connected and drains to the lower most drip line even after effluent flow is suspended from the waste treatment system.